Asthma is a very common and important respiratory illness in children. However, the majority of known information regarding asthma airway inflammation is from studies in adults. We hypothesize that asthma airway inflammation in children is unique with specific identifiable mediators. We further hypothesize that lower airway epithelial cells are a principal target for airway inflammatory cells in asthma producing interactions that are associated with proinflammatory cytokine release and cellular receptor expression. To test this hypothesis, we propose the following specific aims: (1) characterize the inflammatory mediators and cells produced in the lower airways of children with asthma and identify the mediators and cells that differentiate asthmatic children from non-asthmatic children; (2) correlate the biochemical findings in the airways to the serologic markers and mediators of asthma and airway inflammation in both asthmatic and non-asthmatic children; and (3) correlate the bronchoalveolar lavage findings with airway physiologic assessment markers of asthma including FEV1, methacholine challenge testing, and allergy skin testing.